1. Field of the Invention
This invention relates to flail-type material spreaders and is directed particularly to improved flails for such material spreaders.
2. Description of the Prior Art
Flail-type material spreaders, such as disclosed in Pat. No. 3.980.239, for example, usually comprise a generally cylindrical tank with a longitudinally-extending shaft carrying flails comprising flexible members terminating in flail heads operable, on rotation of the shaft, to discharge material from the tank. A wide range of materials may be handled by such a spreader which is much in use on farms where it has to handle dry manure, sticky manure, sloppy manure, liquid manure, wet manure and frozen manure. Different types of animal bedding may be mixed with the manure which varies its consistency. The flail-type material spreader handles, to some degree of satisfaction, all of these various types of material and is, therefore, very versatile and adaptable to a wide range of conditions on farms.
The tank is mounted on a wheeled frame and usually extends in the direction of travel, the material being discharged by the flails throwing the material through an opening in the side of the tank. The rotor shaft is normally connected to the power-take-off of a tractor by which the spreader is towed across a field, in the case of farm use. The shaft is drivable over a range of speeds, the selected speed depending upon the required discharge action. The flails are usually of the chain type, as already mentioned, and different arrangements thereof may be employed. The simplest is a single row of flails connected along one side of the shaft. In another arrangement, two rows of diametrially opposed flails are provided on the shaft with the flails of the two rows either aligned or offset. Three rows of flails may be connected to the shaft at 120.degree. intervals. In another arrangement, a single row of flails may be connected to the shaft along a spiral path or connected along the outer edge of an auger provided on the shaft. In some spreaders, four rows of flails are connected to the shaft at 90.degree. intervals therearound.
Most flail-type spreaders have front and rear starter flails which act as impactors and are often pivotally mounted on the outer ends of rotor arms rigidly secured to the shaft.
The dry, wet or sticky manure is usually loaded into the spreader tank so that it is piled above the rotor shaft. Since the spreader is not operating during the loading, the flexible chains extend downwardly into the tank and the manure piles around the chains and holds them in this position. Or rotation of the shaft, the chains wrap around the rotor shaft and form an axial passage through the material without discharging the material from the spreader. The front and rear starter flails, due to their construction, start the discharge of the material. As the ends of the tank are cleared, the chain flails adjacent the starter flails start to unravel from the shaft and discharge the material from the tank. The material is thus progressively discharged from the end of the tank to the middle.
With a liquid or semi-liquid (slurry) material at a level about the shaft, the resistance of the liquid prevents the flails from throwing any significant amount of liquid out of the tank which greatly prolongs the unloading process. The majority of the liquid material is therefore discharged initially by the starter flails, as with solid materials. However, once the level of the liquid drops below the shaft, the flails become operative and assume an extended position to discharge the liquid or slurry along the entire length of the tank.
To the present time, although flail-type material spreaders have been used for a number of years, pivotable starter flails have not changed much and yet they are not entirely satisfactory. Known starter flails often comprise rotor arms of metal strip rigidly attached to the rotor shaft and having a flat member welded perpendicular thereto either along the longitudinal axis of the rotor arms or towards the leading edge thereof, and these flails operate to throw material out of the opening of the tank by brute force of impact of the flat member thereon.
Known flail heads, other than starter flails, comprise simple T-shaped metal members connected to the ends of the chains to assist in the breaking up of solid material and to impel manure out of the tank. In liquid or semi-liquid materials, however, these flails are not very efficient.